Phacoemulsification hook tip

ABSTRACT

In various embodiments, a phacoemulsification cutting tip with a straight shaft and an angled portion off of the straight shaft may include a hook on the angled portion to move an axis of rotation of the cutting tip closer to alignment with an extended centerline of the shaft. The cutting tip may be configured to torsionally rotate back and forth on an axis perpendicular to a centerline of the shaft (e.g., rotation around a y-axis). In some embodiments, lateral vibrations (e.g., side to side along an x-axis or z-axis perpendicular to the y-axis) that result from torsional rotation around the y-axis in a cutting tip without the hook may be reduced through use of the hook to balance the otherwise eccentrically weighted hook.

FIELD OF THE INVENTION

The present invention generally pertains to phacoemulsification. Moreparticularly, but not by way of limitation, the present inventionpertains to phacoemulsification cutting tips.

DESCRIPTION OF THE RELATED ART

The human eye in its simplest terms functions to provide vision bytransmitting light through a clear outer portion called the cornea, andfocusing the image by way of the lens onto the retina. The quality ofthe focused image depends on many factors including the size and shapeof the eye, and the transparency of the cornea and lens.

When age or disease causes the lens to become less transparent, visiondeteriorates because of the diminished light which can be transmitted tothe retina. This deficiency in the lens of the eye is medically known asa cataract. An accepted treatment for this condition is surgical removalof the lens and replacement of the lens function by an intraocular lens(IOL).

Cataractous lenses may be removed by a surgical technique calledphacoemulsification. During this procedure, a thin phacoemulsificationcutting tip may be inserted into the diseased lens and vibratedultrasonically. The vibrating cutting tip may liquefy or emulsify thelens so that the lens may be aspirated out of the eye. The diseasedlens, once removed, may be replaced by an artificial lens.

SUMMARY OF THE INVENTION

In various embodiments, a phacoemulsification tip with a straight shaftand an angled portion off of the straight shaft may include a hook onthe angled portion to move an axis of rotation of the tip closer toalignment with a centerline of the shaft. The tip may be configured totorsionally rotate back and forth on an axis perpendicular to acenterline of the shaft (e.g., rotation around a y-axis). In someembodiments, lateral vibrations (e.g., side to side along an x-axis orz-axis perpendicular to the y-axis) that result from torsional rotationaround the y-axis in a tip without the hook may be reduced through useof the hook to balance the otherwise eccentrically weighted hook.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference ismade to the following description taken in conjunction with theaccompanying drawings in which:

FIGS. 1 a-b illustrate a phacoemulsification tip with a distal end thatis angled relative to centerline of the tip shaft;

FIG. 2 a illustrates a phacoemulsification surgical console connected toa handpiece through an irrigation line and an aspiration line, accordingto an embodiment;

FIG. 2 b illustrates an ultrasonic horn attached to the hooked tip,according to an embodiment;

FIGS. 3 a-b illustrate an embodiment of the hooked tip;

FIG. 4 illustrates motion of the hooked tip, according to an embodiment;

FIG. 5 illustrates a hooked tip inserted into an incision in the eye,according to an embodiment; and

FIGS. 6 a-c illustrate additional embodiments of the hooked tip.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are intended to provide a further explanation of the presentinvention as claimed.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIGS. 1 a-b illustrate a phacoemulsification cutting tip 100 with adistal end that is angled relative to a tip shaft 108. The cutting tip100 may include a predominantly straight shaft 108 with the far distalportion bent on an angle 102 (e.g., approximately a 20 degree bend).Other angles are also contemplated (e.g., 5 degree bend, 35 degree bend,etc). The distal portion may have a flared and/or beveled distal end.The cutting tip 100 may be used in conjunction with aphacoemulsification handpiece 204 (e.g., see FIG. 2). When used with thehandpiece 204, the cutting tip 100 may use longitudinal movement and/ortransverse movement. Cutting tip 100 may be eccentrically weighted withtip material on only one side of the extended shaft centerline 104(because of angle 102). As used herein “extended shaft centerline”refers to a line that includes and is collinear with the shaftcenterline (as illustrated in, for example, FIGS. 1 a and 3 a). Theeccentrically weighted cutting tip may therefore have a center ofrotation 106 that is displaced from the extended shaft centerline 104 ofthe shaft 108 through at least a portion of the cutting tip 100 (e.g.,at least along the bottom 10% of the length of the cutting tip 100).Other portions of the length are also contemplated (e.g., the center ofrotation 106 maybe displaced from the extended shaft centerline 104through 50% of the length or gradually over the entire length of thecutting tip 100). For example, as seen in FIG. 3 a, the center ofrotation 106 may follow an angle of approximately 0 to 10 degrees offparallel with the extended shaft centerline 104. Other angles andconfigurations of the center of rotation 106 are also contemplated(e.g., the center of rotation 106 may be displaced from and parallel tothe extended shaft centerline 104). Rotating the eccentrically weightedtip and/or the resistance of fluid against the moving cutting tip 100may cause lateral vibrations in the eccentrically weighted cutting tip100 when the cutting tip 100 is vibrated (e.g., rotationally and/orlongitudinally) through the shaft 108.

FIG. 2 a illustrates a phacoemulsification surgical console 214connected to a handpiece 204 through an irrigation line 206 and anaspiration line 208. In some embodiments, power may be supplied tohandpiece 204 through electrical cable 210 and flow through lines 206and 208 may be controlled by a user (e.g., via footswitch 212) toperform a phacoemulsification procedure. One example of a handpiece fora phacoemulsification procedure is described in U.S. Patent ApplicationPublication entitled “Ultrasound Handpiece,” Publication No.2006/0041220, Ser. No. 11/183,591, by Mikhail Boukhny, James Y. Chon,and Ahmad Salehi filed Jul. 18, 2005, which is hereby incorporated byreference in its entirety as though fully and completely set forthherein.

In some embodiments, the handpiece 204 may include at least one set ofpiezoelectric elements 227 polarized to produce longitudinal motion whenexcited at a relevant resonant frequency. As seen in FIG. 2 b, thepiezoelectric crystals 227 may be connected to an ultrasonic horn 216 towhich a cutting tip 202 is attached. The horn 216 and/or the cutting tip202 may include a plurality of diagonal slits or grooves 224. The slitsor grooves 224 may produce torsional movement in the cutting tip 202when the piezoelectric crystals are excited at a resonant frequency.Movement of the cutting tip 202 caused by the grooves 224 engaging fixedelements in the handpiece 204 may include a torsional rotationalcomponent relative to an axis of rotation collinear with a centerline ofthe horn 216.

In some embodiments, handpiece 204 may be coupled to aphacoemulsification cutting tip 202. As seen in FIG. 3 a, thephacoemulsification cutting tip 202 may include a hook 310 located nearangle 312 in a shaft 304 of the cutting tip 202. In some embodiments,the hook 310 may include a curve, a bump, or an elbow geometry that mayact as a counterweight by placing tip material on an opposing side ofthe extended shaft centerline 316 than tip material angled away from theextended shaft centerline below angle 312. In some embodiments, thecutting tip may have a diameter in a range of approximately 0.5 mm to 2mm (e.g., 1.5 mm). In some embodiments, the cutting tip may have aflared tip with a diameter at a top of the tip of approximately 1.5 mmand a diameter near a distal end of the tip of 0.5 mm (other diametersand configurations are also contemplated). In one embodiment, thecutting tip 202 may have a length of approximately 1 and ⅜ inches with ahook portion length of approximately 5/32 inches. Other dimensions arealso contemplated. Hook 310 may act to move a center of rotation 306 tolie near (e.g., within a distance 314 of 0.25*shaft diameter) or onextended shaft centerline 316. Other distances between the center ofrotation 306 and the extended shaft centerline 316 are also contemplated(e.g., within a distance of 0.5*shaft diameter, within a distance equalto the shaft diameter, etc). In some embodiments, motion of a topportion of the cutting tip 100 may be constrained due to its closeproximity to the horn gripping the cutting tip 100 such that an axis ofrotation of the top of the cutting tip 100 may lie along the extendedshaft centerline 316 while a distal end of the cutting tip 100 (e.g.,along approximately 10% of the bottom length of the cutting tip 100) maybe distanced from the extended shaft centerline 316. In someembodiments, there may be a gradual displacement of the center ofrotation 306 relative to the extended shaft centerline 316 from the topof the cutting tip 100 to the bottom of the cutting tip 100. As notedabove, the hook 310 may effectively move the center of rotation 306 tolie near (e.g., within a distance 314 of 0.25*shaft diameter) or onextended shaft centerline 316 at the bottom portion of the cutting tip100.

The hook 310 may include various geometries of varying angle, length ordepth of bend, etc. (e.g., see FIGS. 3 a and 6 a-6 c). The geometry ofthe hook 310 may also be configured to move a line through the center ofmass of the tip and parallel to the extended shaft centerline of thecutting tip 202 closer to the extended shaft centerline 316 to reduceeccentric movement (including lateral vibrations) in the cutting tip 202during rotational and/or longitudinal movements.

In some embodiments, the cutting tip 202 may be ultrasonicallytorsionally vibrated along a small arc (e.g., +/−5 degrees). Thetorsional vibrations of cutting tip 202 may result in lateral motions inthe shaft 304 and cutting tip 202. The whipping motion may include aside to side torsional motion of the cutting tip 202 perpendicular tothe extended shaft centerline 316 (e.g., rotation around the y-axis asseen in FIG. 3 a). In some embodiments, lateral vibrations (e.g., sideto side along the x-axis or z-axis as seen in FIG. 3 a) that result fromthe eccentrically weighted cutting tip and/or fluid resistance againstthe back and forth torsional rotation around the y-axis (e.g., cuttingtip 100 in FIG. 1 a) may be reduced through use of the hook 310 tobalance the otherwise eccentrically weighted hook.

As seen in FIG. 4, in some embodiments, the cutting tip 202 maytorsionally rotate back and forth through approximately a 10 degree arc(e.g., plus or minus 5 degrees off center (see middle diagram 2)). Insome embodiments, the cutting tip 202 may rotate back and forth at arate of approximately 31 kHz. Other arcs and rates are alsocontemplated. For example, an arc of plus or minus 20 degrees and/or arate of 10-60 kHz may be used. The arc shown in FIG. 4 is exaggerated toshow movement (i.e., the total arc shown is 180 degrees, whereas thecutting tip may have limited back and forth rotation on a 10 degreearc).

As seen in FIG. 5, when used to perform phacoemulsification, the ends ofthe cutting tip 202 and an irrigating sleeve 226 may be inserted into asmall incision in the cornea 501, sclera 507, or other location in theeye tissue to gain access to, for example, the anterior chamber 503 ofthe eye 509. In various embodiments, a portion or all of the cutting tip202 may be inside the irrigating sleeve 226. The cutting tip 202 may beultrasonically torsionally vibrated along its longitudinal axis withinthe irrigating sleeve 226 by a crystal-driven ultrasonic horn 216,thereby emulsifying upon contact the selected tissue in situ. The hollowbore of the cutting tip 202 may communicate with the bore in the hornthat in turn may communicate with the aspiration line from the handpiece204 to the console 214 (e.g., see FIG. 2 a). A reduced pressure orvacuum source in the console 214 may draw or aspirate the emulsifiedtissue from the eye 509 through an open end of the cutting tip 202, thebore of the cutting tip 202, the horn bore, and the aspiration line 208and into a collection device. The aspiration of emulsified tissue may beaided by a saline flushing solution or irrigant that may be injectedinto the surgical site through the small annular gap between the insidesurface of the irrigating sleeve 226 and an outside surface of thecutting tip 202.

Cutting tip 202 may be made from stainless steel or titanium (othermaterials may also be used). Cutting tip 202 may have an overall lengthof between 0.50 inches and 1.50 inches (e.g., 1.20 inches). Otherlengths are also contemplated. Cutting tip 202 may be formed usingconventional metalworking technology and may be electropolished. Shaft304 may be generally tubular, with an outside diameter of between 0.005inches and 0.100 inches and an inside diameter of between 0.001 inchesand 0.090 inches (other diameters are also contemplated).

Various modifications may be made to the presented embodiments by aperson of ordinary skill in the art. Other embodiments of the presentinvention will also be apparent to those skilled in the art fromconsideration of the present specification and practice of the presentinvention disclosed herein. It is intended that the presentspecification and examples be considered as exemplary only with a truescope and spirit of the invention being indicated by the followingclaims and equivalents thereof.

1. A cutting tip for a surgical handpiece, comprising: a shaft; an angled portion coupled to the shaft; wherein the angled portion further comprises a hook; and wherein the shaft, angled portion, and hook are comprised in a single piece; wherein a distal portion of the cutting tip has an axis of rotation relative to the shaft that is substantially aligned with an extended shaft centerline.
 2. The cutting tip as recited in claim 1, wherein substantially aligned comprises the axis of rotation being offset from the extended shaft centerline by a distance less than 0.25*shaft diameter.
 3. The cutting tip as recited in claim 1, wherein substantially aligned comprises the axis of rotation being offset from the extended shaft centerline by a distance less than 0.5*shaft diameter.
 4. The cutting tip of claim 1, wherein a shortest distance between the axis of rotation of the cutting tip without the hook and the extended shaft centerline would be greater than a shortest distance between the axis of rotation of the cutting tip with the hook and the extended shaft centerline.
 5. The cutting tip of claim 1, wherein the cutting tip is configured to be vibrated torsionally back and forth at approximately plus 5 degrees to minus 5 degrees from center.
 6. The cutting tip of claim 1, wherein the cutting tip is configured to be torsionally rotated back and forth about an axis that is parallel with an extended shaft centerline; and wherein the third portion balances the cutting tip to reduce lateral vibrations back and forth perpendicular to the axis.
 7. The cutting tip of claim 1, wherein substantially aligned with the extended shaft centerline includes parallel with the extended shaft centerline to 5 degrees off parallel with the extended shaft centerline.
 8. The cutting tip of claim 1, wherein substantially aligned with the extended shaft centerline comprises a range of parallel with the extended shaft centerline to 10 degrees off parallel with the extended shaft centerline.
 9. The cutting tip of claim 1, wherein the distal portion of the cutting tip is approximately 10% of a length of an end of the cutting tip farthest from the handpiece.
 10. A cutting tip for a surgical handpiece, comprising: a first portion comprising a shaft; a second portion forming an angle with the first portion; a third portion forming a hook; and a distal end; wherein the first portion, second portion, third portion and distal end are comprised in a single piece; wherein the second portion, third portion, and distal end together have an axis of rotation relative to the shaft that is substantially aligned with the extended shaft centerline.
 11. The cutting tip as recited in claim 10, wherein substantially aligned comprises the axis of rotation being offset from the extended shaft centerline by a distance less than 0.25*shaft diameter.
 12. The cutting tip as recited in claim 10, wherein substantially aligned comprises the axis of rotation being offset from the extended shaft centerline by a distance less than 0.5*shaft diameter.
 13. The cutting tip of claim 10, wherein a shortest distance between the axis of rotation of the cutting tip without the hook and the extended shaft centerline would be greater than a shortest distance between the axis of rotation of the cutting tip with the hook and the extended shaft centerline.
 14. The cutting tip of claim 10, wherein the cutting tip is configured to be vibrated torsionally back and forth at approximately plus 5 degrees to minus 5 degrees from center.
 15. The cutting tip of claim 10, wherein the cutting tip is configured to be torsionally rotated back and forth on an axis that is parallel with the extended shaft centerline; and wherein the third portion balances the cutting tip to reduce lateral vibrations back and forth perpendicular to the axis.
 16. The cutting tip of claim 10, wherein substantially aligned comprises a range of parallel with the extended shaft centerline to 5 degrees off parallel with the extended shaft centerline.
 17. The cutting tip of claim 10, wherein substantially aligned with the extended shaft centerline comprises a range of parallel with the extended shaft centerline to 10 degrees off parallel with the extended shaft centerline.
 18. The cutting tip of claim 10, wherein the second portion, third portion, and distal end of the cutting tip are approximately 10% of a length of the cutting tip.
 19. The cutting tip of claim 10, wherein the hook configuration changes directions at least three times relative to the extended shaft centerline. 